I began my career as a prosecutor in the Fourth Judicial Circuit where I worked for legendary State Attorney Ed Austin. While there, I prosecuted cases ranging from DUI to murder.
I left the State Attorney's Office to work as an associate for the firm of Kopelousos, Head, Smith, Townsend & Metcalf, a highly-respected AV- rated firm based in Clay County, Florida. After trying numerous criminal and complex civil cases, I became a shareholder in the firm which then became Head, Smith, Metcalf, Aguilar, Sieron & Moss, P.A. The current law firm is a successor to that firm.
Several years ago, I decided to concentrate primarily on criminal defense and associated administrative and civil cases. I've been honored to have earned the respect of my peers and the judiciary, having received an AV-Preeminent rating (highest possible for legal ability and ethics) by Martindale-Hubbell for over 20 years.
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Chat withState: Florida
Acquired: 1985
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1045 North Orange Avenue, Green Cove Springs, FL, 32043-2529
Showing 1 - 2 of 2 client reviews from Avvo
Posted by Andrea | July 29, 2019 | Hired Attorney
When our family contacted Aguilar & Sieron, our son was in a desperate situation that other lawyers told us would lead to life...or, best case scenario, a 15-year or more sentence. But Mr. Sieron and his staff patiently and empathetically worked with us, assuring us that while things looked bleak, th...
Posted by anonymous | June 21, 2019 | Hired Attorney
Mark has represented me in a myriad of legal issues over the past 25 years. His knowledge and expertise is unmatched. He has always represented me honestly and tenaciously. He has protected my rights and always obtained an outcome that I was very satisfied with.
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2020
AV Preeminent 5.0 out of 5 Peer Review Rated, Martindale-Hubbell
2020
Super Lawyer, SuperLawyers
2019
Super Lawyer, SuperLawyers
2014
Top 100 Florida Trial Lawyers, National Trial Lawyers Association
2012
Top Criminal Defense Lawyers, 904 Magazine
2006 - Present
Managing Partner, Aguilar & Sieron,, P.A.
1993 - 2006
Associate/Shareholder, Kopelousos, Head, Smith, Townsend & Metcalf, P.A.
1984 - 1984
Certified Intern, State Attorney's Office
1984 - 1987
Prosecutor, State Attorney's Office
1983 - 1983
Legal Intern, Law Offices of Ferrin Campbell, P.A.
2005 - Present
Northeast Florida Association of Criminal Defense LawyersMember
1996 - Present
Florida Association of Criminal Defense LawyersMember
1996 - Present
National Association of Criminal Defense LawyersMember
1988 - Present
Jacksonville Bar AssociationMember
1993 - 1995
Clay County Bar AssociationPast President
1990 - 1991
Clay County Bar AssociationPast President
1984
JD - Juris Doctor
1981
BS - Bachelor of Science
1995
Third Party Liens
N/A
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